Info file emacs, produced by texinfo-format-buffer   -*-Text-*-
from file emacs.tex

This file documents the GNU Emacs editor.

Copyright (C) 1985, 1986 Richard M. Stallman.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided also that the
sections entitled "The GNU Manifesto", "Distribution" and "GNU Emacs
General Public License" are included exactly as in the original, and
provided that the entire resulting derived work is distributed under the
terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that the sections entitled "The GNU Manifesto", "Distribution"
and "GNU Emacs General Public License" may be included in a translation
approved by the author instead of in the original English.


File: emacs  Node: Top, Up: (DIR), Next: Distrib

The Emacs Editor
****************

Emacs is the extensible, customizable, self-documenting real-time
display editor.  This Info file describes how to edit with Emacs
and some of how to customize it, but not how to extend it.

* Menu:

* Distrib::     How to get the latest Emacs distribution.
* License::     The GNU Emacs General Public License gives you permission
		to redistribute GNU Emacs on certain terms; and also
		explains that there is no warranty.
* Intro::       An introduction to Emacs concepts.
* Glossary::    The glossary.
* Manifesto::   What's GNU?  Gnu's Not Unix!

Indexes, nodes containing large menus
* Key Index::      An item for each standard Emacs key sequence.
* Command Index::  An item for each command name.
* Variable Index:: An item for each documented variable.
* Concept Index::  An item for each concept.

Important General Concepts
* Screen::      How to interpret what you see on the screen.
* Characters::  Emacs's character sets for file contents and for keyboard.
* Keys::        Key sequences: what you type to request one editing action.
* Commands::    Commands: named functions run by key sequences to do editing.
* Entering Emacs::    Starting Emacs from the shell.
* Command Switches::  Hairy startup options.
* Exiting::     Stopping or killing Emacs.
* Basic::       The most basic editing commands.
* Undo::        Undoing recently made changes in the text.
* Minibuffer::  Entering arguments that are prompted for.
* M-x::         Invoking commands by their names.
* Help::        Commands for asking Emacs about its commands.

Important Text-Changing Commands
* Mark::        The mark: how to delimit a "region" of text.
* Killing::     Killing text.
* Yanking::     Recovering killed text.  Moving text.
* Accumulating Text::
                Other ways of copying text.
* Rectangles::  Operating on the text inside a rectangle on the screen.
* Registers::   Saving a text string or a location in the buffer.
* Display::     Controlling what text is displayed.
* Search::      Finding or replacing occurrences of a string.
* Fixit::       Commands especially useful for fixing typos.

Larger Units of Text
* Files::       All about handling files.
* Buffers::     Multiple buffers; editing several files at once.
* Windows::     Viewing two pieces of text at once.

Advanced Features
* Major Modes:: Text mode vs. Lisp mode vs. C mode ...
* Indentation:: Editing the white space at the beginnings of lines.
* Text::        Commands and modes for editing English.
* Programs::    Commands and modes for editing programs.
* Running::     Compiling, running and debugging programs.
* Abbrevs::     How to define text abbreviations to reduce
                 the number of characters you must type.
* Picture::     Editing pictures made up of characters
                 using the quarter-plane screen model.
* Sending Mail::Sending mail in Emacs.
* Rmail::       Reading mail in Emacs.
* Recursive Edit::
                A command can allow you to do editing
                 "within the command".  This is called a
                 `recursive editing level'.
* Narrowing::   Restricting display and editing to a portion
                 of the buffer.
* Sorting::	Sorting lines, paragraphs or pages within Emacs.
* Shell::       Executing shell commands from Emacs.
* Hardcopy::	Printing buffers or regions.
* Dissociated Press::  Dissociating text for fun.
* Amusements::         Various games and hacks.
* Emulation::	       Emulating some other editors with Emacs.
* Customization::      Modifying the behavior of Emacs.

Recovery from Problems.
* Quitting::    Quitting and aborting.
* Lossage::     What to do if Emacs is hung or malfunctioning.
* Bugs::        How and when to report a bug.

Here are some other nodes which are really inferiors of the ones
already listed, mentioned here so you can get to them in one step:

Subnodes of Screen
* Point::	The place in the text where editing commands operate.
* Echo Area::   Short messages appear at the bottom of the screen.
* Mode Line::	Interpreting the mode line.

Subnodes of Basic
* Blank Lines:: Commands to make or delete blank lines.
* Continuation Lines:: Lines too wide for the screen.
* Position Info::      What page, line, row, or column is point on?
* Arguments::          Giving numeric arguments to commands.

Subnodes of Minibuffer
* Minibuffer File::    Entering file names with the minibuffer.
* Minibuffer Edit::    How to edit in the minibuffer.
* Completion::  An abbreviation facility for minibuffer input.
* Repetition::  Re-executing previous commands that used the minibuffer.

Subnodes of Mark
* Setting Mark::       Commands to set the mark.
* Using Region::       Summary of ways to operate on contents of the region.
* Marking Objects::    Commands to put region around textual units.
* Mark Ring::          Previous mark positions saved so you can go back there.

Subnodes of Yanking
* Kill Ring::          Where killed text is stored.  Basic yanking.
* Appending Kills::    Several kills in a row all yank together.
* Earlier Kills::      Yanking something killed some time ago.

Subnodes of Registers
* RegPos::             Saving positions in registers.
* RegText::            Saving text in registers.
* RegRect::            Saving rectangles in registers.

Subnodes of Display
* Scrolling::	           Moving text up and down in a window.
* Horizontal Scrolling::   Moving text left and right in a window.
* Selective Display::      Hiding lines with lots of indentation.
* Display Vars::           Information on variables for customizing display.

Subnodes of Search
* Incremental Search::     Search happens as you type the string.
* Nonincremental Search::  Specify entire string and then search.
* Word Search:: 	   Search for sequence of words.
* Regexp Search::	   Search for match for a regexp.
* Regexps::     	   Syntax of regular expressions.
* Search Case::		   To ignore case while searching, or not.
* Replace::     	   Search, and replace some or all matches.
* Unconditional Replace::  Everything about replacement except for querying.
* Query Replace::          How to use querying.
* Other Repeating Search:: Operating on all matches for some regexp.

Subnodes of Fixit
* Kill Errors:: Commands to kill a batch of recently entered text.
* Transpose::   Exchanging two characters, words, lines, lists...
* Fixing Case:: Correcting case of last word entered.
* Spelling::    Apply spelling checker to a word, or a whole file.

Subnodes of Files
* File Names::  How to type and edit file name arguments.
* Visiting::    Visiting a file prepares Emacs to edit the file.
* Saving::      Saving makes your changes permanent.
* Backup::      How Emacs saves the old version of your file.
* Interlocking::How Emacs protects against simultaneous editing
                 of one file by two users.
* Reverting::   Reverting cancels all the changes not saved.
* Auto Save::   Auto Save periodically protects against loss of data.
* ListDir::     Listing the contents of a file directory.
* Dired::       "Editing" a directory to delete, rename, etc.
                 the files in it.
* Misc File Ops:: Other things you can do on files.

Subnodes of Buffers
* Select Buffer::   Creating a new buffer or reselecting an old one.
* List Buffers::    Getting a list of buffers that exist.
* Misc Buffer::     Renaming; changing read-only status.
* Kill Buffer::     Killing buffers you no longer need.
* Several Buffers:: How to go through the list of all buffers
                     and operate variously on several of them.

Subnodes of Windows
* Basic Window::    Introduction to Emacs windows.
* Split Window::    New windows are made by splitting existing windows.
* Other Window::    Moving to another window or doing something to it.
* Pop Up Window::   Finding a file or buffer in another window.
* Change Window::   Deleting windows and changing their sizes.

Subnodes of Indentation
* Indentation Commands:: Various commands and techniques for indentation.
* Tab Stops::   You can set arbitrary "tab stops" and then
                 indent to the next tab stop when you want to.
* Just Spaces:: You can request indentation using just spaces.

Subnodes of Text
* Text Mode::   The major mode for editing text files.
* Nroff Mode::  The major mode for editing input to the formatter nroff.
* TeX Mode::    The major mode for editing input to the formatter TeX.
* Outline Mode::The major mode for editing outlines.
* Words::       Moving over and killing words.
* Sentences::   Moving over and killing sentences.
* Paragraphs::	Moving over paragraphs.
* Pages::	Moving over pages.
* Filling::     Filling or justifying text
* Case::        Changing the case of text

Subnodes of Programs
* Program Modes::       Major modes for editing programs.
* Lists::       Expressions with balanced parentheses.
                 There are editing commands to operate on them.
* Defuns::      Each program is made up of separate functions.
                 There are editing commands to operate on them.
* Grinding::    Adjusting indentation to show the nesting.
* Matching::    Insertion of a close-delimiter flashes matching open.
* Comments::    Inserting, illing and aligning comments.
* Balanced Editing::    Inserting two matching parentheses at once, etc.
* Lisp Completion::     Completion on symbol names in Lisp code.
* Documentation::       Getting documentation of functions you plan to call.
* Change Log::  Maintaining a change history for your program.
* Tags::        Go direct to any function in your program in one
                 command.  Tags remembers which file it is in.
* Fortran::	Fortran mode and its special features.

Subnodes of Running
* Compilation::       Compiling programs in languages other than Lisp
                       (C, Pascal, etc.)
* Lisp Modes::        Various modes for editing Lisp programs, with
                       different facilities for running the Lisp programs.
* Lisp Libraries::    Creating Lisp programs to run in Emacs.
* Lisp Interaction::  Executing Lisp in an Emacs buffer.
* Lisp Eval::         Executing a single Lisp expression in Emacs.
* Lisp Debug::        Debugging Lisp programs running in Emacs.
* External Lisp::     Communicating through Emacs with a separate Lisp.

Subnodes of Abbrevs
* Defining Abbrevs::  Defining an abbrev, so it will expand when typed.
* Expanding Abbrevs:: Controlling expansion: prefixes, canceling expansion.
* Editing Abbrevs::   Viewing or editing the entire list of defined abbrevs.
* Saving Abbrevs::    Saving the entire list of abbrevs for another session.
* Dynamic Abbrevs::   Abbreviations for words already in the buffer.

Subnodes of Picture
* Basic Picture::     Basic concepts and simple commands of Picture Mode.
* Insert in Picture:: Controlling direction of cursor motion
                       after "self-inserting" characters.
* Tabs in Picture::   Various features for tab stops and indentation.
* Rectangles in Picture:: Clearing and superimposing rectangles.

Subnodes of Sending Mail
* Mail Format::       Format of the mail being composed.
* Mail Headers::      Details of allowed mail header fields.
* Mail Mode::         Special commands for editing mail being composed.

Subnodes of Rmail
* Rmail Scrolling::   Scrolling through a message.
* Rmail Motion::      Moving to another message.
* Rmail Deletion::    Deleting and expunging messages.
* Rmail Inbox::       How mail gets into the Rmail file.
* Rmail Files::       Using multiple Rmail files.
* Rmail Output::      Copying message out to files.
* Rmail Labels::      Classifying messages by labeling them.
* Rmail Summary::     Summaries show brief info on many messages.
* Rmail Reply::       Sending replies to messages you are viewing.
* Rmail Editing::     Editing message text and headers in Rmail.
* Rmail Digest::      Extracting the messages from a digest message.

Subnodes of Shell
* Single Shell::      Commands to run one shell command and return.
* Interactive Shell:: Permanent shell taking input via Emacs.
* Shell Mode::        Special Emacs commands used with permanent shell.

Subnodes of Customization
* Minor Modes::       Each minor mode is one feature you can turn on
                       independently of any others.
* Variables::         Many Emacs commands examine Emacs variables
                       to decide what to do; by setting variables,
                       you can control their functioning.
* Examining::         Examining or setting one variable's value.
* Edit Options::      Examining or editing list of all variables' values.
* Locals::            Per-buffer values of variables.
* File Variables::    How files can specify variable values.
* Keyboard Macros::   A keyboard macro records a sequence of keystrokes
                       to be replayed with a single command.
* Key Bindings::      The keymaps say what command each key runs.
                       By changing them, you can "redefine keys".
* Keymaps::           Definition of the keymap data structure.
* Rebinding::         How to redefine one key's meaning conveniently.
* Disabling::         Disabling a command means confirmation is required
                       before it can be executed.  This is done to protect
                       beginners from surprises.
* Syntax::            The syntax table controls how words and expressions
                       are parsed.
* Init File::         How to write common customizations in the `.emacs' file.

Subnodes of Lossage (and recovery)
* Stuck Recursive::   `[...]' in mode line around the parentheses.
* Screen Garbled::    Garbage on the screen.
* Text Garbled::      Garbage in the text.
* Unasked-for Search::Spontaneous entry to incremental search.
* Emergency Escape::  Emergency escape---
                       What to do if Emacs stops responding.
* Total Frustration:: When you are at your wits' end.



File: emacs  Node: Distrib, Prev: Top, Up: Top, Next: License

Distribution
************

GNU Emacs is "free"; this means that everyone is free to use it and
free to redistribute it on a free basis.  GNU Emacs is not in the public
domain; it is copyrighted and there are restrictions on its distribution,
but these restrictions are designed to permit everything that a good
cooperating citizen would want to do.  What is not allowed is to try to
prevent others from further sharing any version of GNU Emacs that they
might get from you.  The precise conditions are found in the GNU Emacs
General Public License that comes with Emacs and also appears following
this section.

The easiest way to get a copy of GNU Emacs is from someone else who has it.
You need not ask for permission to do so, or tell any one else; just copy
it.

If you have access to the Internet, you can get the latest distribution
version of GNU Emacs from host `prep.ai.mit.edu' using anonymous
login.  See the file `/u2/emacs/GETTING.GNU.SOFTWARE' on that host
to find out about your options for copying and which files to use.

You may also receive GNU Emacs when you buy a computer.  Computer
manufacturers are free to distribute copies on the same terms that apply to
everyone else.  These terms require them to give you the full sources,
including whatever changes they may have made, and to permit you to
redistribute the GNU Emacs received from them under the usual terms of the
General Public License.  In other words, the program must be free for you
when you get it, not just free for the manufacturer.

If you cannot get a copy in any of those ways, you can order one from the
Free Software Foundation.  Though Emacs itself is free, our distribution
service is not.  An order form is included at the end of manuals printed by
the Foundation.  It is also included in the file `etc/DISTRIB' in the
Emacs distribution.  For further information, write to

     Free Software Foundation
     1000 Mass Ave
     Cambridge, MA 02138
     USA

The income from distribution fees goes to support the foundation's
purpose: the development of more free software to distribute just like
GNU Emacs.

If you find GNU Emacs useful, please send a donation to the Free
Software Foundation.  This will help support development of the rest of the
GNU system, and other useful software beyond that.  Your donation is tax
deductible.


File: emacs  Node: License, Prev: Distrib, Up: Top, Next: Intro

GNU Emacs General Public License
********************************
                         (Clarified 20 March 1987)

  The license agreements of most software companies keep you at the
mercy of those companies.  By contrast, our general public license is
intended to give everyone the right to share GNU Emacs.  To make
sure that you get the rights we want you to have, we need to make
restrictions that forbid anyone to deny you these rights or to ask you
to surrender the rights.  Hence this license agreement.

  Specifically, we want to make sure that you have the right to give
away copies of Emacs, that you receive source code or else can get it
if you want it, that you can change Emacs or use pieces of it in new
free programs, and that you know you can do these things.

  To make sure that everyone has such rights, we have to forbid you to
deprive anyone else of these rights.  For example, if you distribute
copies of Emacs, you must give the recipients all the rights that you
have.  You must make sure that they, too, receive or can get the
source code.  And you must tell them their rights.

  Also, for our own protection, we must make certain that everyone
finds out that there is no warranty for GNU Emacs.  If Emacs is
modified by someone else and passed on, we want its recipients to know
that what they have is not what we distributed, so that any problems
introduced by others will not reflect on our reputation.

  Therefore we (Richard Stallman and the Free Software Foundation, Inc.)
make the following terms which say what you must do to be allowed to
distribute or change GNU Emacs.


Copying Policies
================

  1. You may copy and distribute verbatim copies of GNU Emacs source code
     as you receive it, in any medium, provided that you conspicuously and
     appropriately publish on each file a valid copyright notice such as
     "Copyright (C) 1987 Free Software Foundation, Inc.",
     containing the year of last change and name of copyright holder for
     the file in question; keep intact the notices on all files that refer
     to this License Agreement and to the absence of any warranty; and give
     any other recipients of the GNU Emacs program a copy of this License
     Agreement along with the program.  You may charge a distribution fee
     for the physical act of transferring a copy.
     
  2. You may modify your copy or copies of GNU Emacs source code or
     any portion of it, and copy and distribute such modifications under
     the terms of Paragraph 1 above, provided that you also do the following:
     
        * cause the modified files to carry prominent notices stating
          who last changed such files and the date of any change; and
          
        * cause the whole of any work that you distribute or publish, that
          in whole or in part contains or is a derivative of GNU Emacs or
          any part thereof, to be licensed at no charge to all third
          parties on terms identical to those contained in this License
          Agreement (except that you may choose to grant more extensive
          warranty protection to third parties, at your option).
          
        * if the modified program serves as a text editor, cause it when
          started running in the simplest and usual way, to print an
          announcement including a valid copyright notice ("Copyright
          (C)", the year of authorship, and all copyright owners'
          names), saying that there is no warranty (or else, saying that
          you provide a warranty) and that users may redistribute the
          program under these conditions, and telling the user how to view
          a copy of this License Agreement.
          
        * You may charge a distribution fee for the physical act of
          transferring a copy, and you may at your option offer warranty
          protection in exchange for a fee.
     
  3. You may copy and distribute GNU Emacs or any portion of it in
     compiled, executable or object code form under the terms of Paragraphs
     1 and 2 above provided that you do the following:
     
        * cause each such copy of GNU Emacs to be accompanied by the
          corresponding machine-readable source code; or
          
        * cause each such copy of GNU Emacs to be accompanied by a written
          offer, with no time limit, to give any third party free (except
          for a nominal shipping charge) machine readable copy of the
          corresponding source code; or
          
        * in the case of a recipient of GNU Emacs in compiled, executable
          or object code form (without the corresponding source code) you
          shall cause copies you distribute to be accompanied by a copy of
          the written offer of source code which you received along with
          the copy of GNU Emacs.
     
  4. You may not copy, sublicense, distribute or transfer GNU Emacs except
     as expressly provided under this License Agreement.  Any attempt
     otherwise to copy, sublicense, distribute or transfer GNU Emacs is
     void and your rights to use GNU Emacs under this License agreement
     shall be automatically terminated.  However, parties who have received
     computer software programs from you with this License Agreement will
     not have their licenses terminated so long as such parties remain in
     full compliance.
     
  5. If you wish to incorporate parts of GNU Emacs into other free programs
     whose distribution conditions are different, write to the Free Software
     Foundation.  We have not yet worked out a simple rule that can be stated
     here, but we will often permit this.  We will be guided by the two goals of
     preserving the free status of all derivatives our free software and of
     promoting the sharing and reuse of software.

Your comments and suggestions about our licensing policies and our
software are welcome!  Please contact the Free Software Foundation, Inc.,
1000 Mass Ave, Cambridge, MA 02138.


NO WARRANTY
===========

  BECAUSE GNU EMACS IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC,
RICHARD M. STALLMAN AND/OR OTHER PARTIES PROVIDE GNU EMACS "AS IS"
WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY
AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE GNU EMACS
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.

 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL FREE SOFTWARE
FOUNDATION, INC., RICHARD M. STALLMAN, AND/OR ANY OTHER PARTY WHO MAY
MODIFY AND REDISTRIBUTE GNU EMACS AS PERMITTED ABOVE, BE LIABLE TO YOU
FOR DAMAGES, INCLUDING ANY LOST PROFITS, LOST MONIES, OR OTHER
SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
INABILITY TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR A
FAILURE OF THE PROGRAM TO OPERATE WITH PROGRAMS NOT DISTRIBUTED BY
FREE SOFTWARE FOUNDATION, INC.) THE PROGRAM, EVEN IF YOU HAVE BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY
OTHER PARTY.


File: emacs  Node: Intro, Prev: License, Up: Top, Next: Glossary

Introduction
************

  You are about to read about GNU Emacs, the GNU incarnation of the
advanced, self-documenting, customizable, extensible real-time display
editor Emacs.  (The `G' in `GNU' is not silent.)

  We say that Emacs is a "display" editor because normally the text
being edited is visible on the screen and is updated automatically as you
type your commands.  *Note Display: Screen.

  We call it a "real-time" editor because the display is updated very
frequently, usually after each character or pair of characters you
type.  This minimizes the amount of information you must keep in your
head as you edit.  *Note Real-time: Basic.

  We call Emacs advanced because it provides facilities that go beyond
simple insertion and deletion: filling of text; automatic indentation of
programs; viewing two or more files at once; and dealing in terms of
characters, words, lines, sentences, paragraphs, and pages, as well as
expressions and comments in several different programming languages.  It is
much easier to type one command meaning "go to the end of the paragraph"
than to find that spot with simple cursor keys.

  "Self-documenting" means that at any time you can type a special
character, `Control-h', to find out what your options are.  You can
also use it to find out what any command does, or to find all the commands
that pertain to a topic.  *Note Help::.

  "Customizable" means that you can change the definitions of Emacs
commands in little ways.  For example, if you use a programming language in
which comments start with `<**' and end with `**>', you can tell
the Emacs comment manipulation commands to use those strings
(*Note Comments::).  Another sort of customization is rearrangement of the
command set.  For example, if you prefer the four basic cursor motion
commands (up, down, left and right) on keys in a diamond pattern on the
keyboard, you can have it.  *Note Customization::.

  "Extensible" means that you can go beyond simple customization and
write entirely new commands, programs in the Lisp language to be run by
Emacs's own Lisp interpreter.  Emacs is an "on-line extensible" system,
which means that it is divided into many functions that call each other,
any of which can be redefined in the middle of an editing session.  Any
part of Emacs can be replaced without making a separate copy of all of
Emacs.  Most of the editing commands of Emacs are written in Lisp already;
the few exceptions could have been written in Lisp but are written in C for
efficiency.  Although only a programmer can write an extension, anybody can
use it afterward.


File: emacs  Node: Screen, Prev: Concept Index, Up: Top, Next: Characters


The Organization of the Screen
******************************

  Emacs divides the screen into several areas, each of which contains
its own sorts of information.  The biggest area, of course, is the one
in which you usually see the text you are editing.

  When you are using Emacs, the screen is divided into a number of
"windows".  Initially there is one text window occupying all but the
last line, plus the special "echo area" or "minibuffer window" in
the last line.  The text window can be subdivided horizontally or
vertically into multiple text windows, each of which can be used for a
different file (*Note Windows::).  The window that the cursor is in is the
"selected window", in which editing takes place.  The other windows are
just for reference unless you select one of them.

  Each text window's last line is a "mode line" which describes what is
going on in that window.  It is in inverse video if the terminal supports
that, and contains text that starts like `-----Emacs: SOMETHING'.  Its
purpose is to indicate what buffer is being displayed above it in the
window; what major and minor modes are in use; and whether the buffer's
text has been changed.

* Menu:

* Point::	The place in the text where editing commands operate.
* Echo Area::   Short messages appear at the bottom of the screen.
* Mode Line::	Interpreting the mode line.


File: emacs  Node: Point, Prev: Screen, Up: Screen, Next: Echo Area

Point
=====

  When Emacs is running, the terminal's cursor shows the location at
which editing commands will take effect.  This location is called
"point".  Other commands move point through the text, so that you
can edit at different places in it.

  While the cursor appears to point AT a character, point should be
thought of as BETWEEN two characters; it points BEFORE the character
that the cursor appears on top of.  Sometimes people speak of "the
cursor" when they mean "point", or speak of commands that move point as
"cursor motion" commands.

  Terminals have only one cursor, and when output is in progress it must
appear where the typing is being done.  This does not mean that point is
moving.  It is only that Emacs has no way to show you the location of point
except when the terminal is idle.

  If you are editing several files in Emacs, each file has its own point
location.  A file that is not being displayed remembers where point is so
that it can be seen when you look at that file again.

  When there are multiple text windows, each window has its own point
location.  The cursor shows the location of point in the selected window.
This also is how you can tell which window is selected.  If the same buffer
appears in more than one window, point can be moved in each window
independently.

  The term `point' comes from the character `.', which was the
command in TECO (the language in which the original Emacs was written)
for accessing the value now called `point'.


File: emacs  Node: Echo Area, Prev: Point, Up: Screen, Next: Mode Line

The Echo Area
=============

  The line at the bottom of the screen (below the mode line) is the
"echo area".  It is used to display small amounts of text for several
purposes.

  "Echoing" means printing out the characters that you type.  Emacs
never echoes single-character commands, and multi-character commands are
echoed only if you pause while typing them.  As soon as you pause for more
than a second in the middle of a command, all the characters of the command
so far are echoed.  This is intended to "prompt" you for the rest of
the command.  Once echoing has started, the rest of the command is echoed
immediately when you type it.  This behavior is designed to give confident
users fast response, while giving hesitant users maximum feedback.  You
can change this behavior by setting a variable (*Note Display Vars::).

  If a command cannot be executed, it may print an "error message" in
the echo area.  Error messages are accompanied by a beep or by flashing the
screen.  Also, any input you have typed ahead is thrown away when an error
happens.

  Some commands print informative messages in the echo area.  These
messages look much like error messages, but they are not announced with a
beep and do not throw away input.  Sometimes the message tells you what the
command has done, when this is not obvious from looking at the text being
edited.  Sometimes the sole purpose of a command is to print a message
giving you specific information.  For example, the command `C-x =' is
used to print a message describing the character position of point in the
text and its current column in the window.  Commands that take a long time
often display messages ending in `...' while they are working, and
add `done' at the end when they are finished.

  The echo area is also used to display the "minibuffer", a window that
is used for reading arguments to commands, such as the name of a file to be
edited.  When the minibuffer is in use, the echo area begins with a prompt
string that usually ends with a colon; also, the cursor appears in that line
because it is the selected window.  You can always get out of the
minibuffer by typing `C-g'.  *Note Minibuffer::.


File: emacs  Node: Mode Line, Prev: Echo Area, Up: Screen

The Mode Line
=============

  Each text window's last line is a "mode line" which describes what is
going on in that window.  When there is only one text window, the mode line
appears right above the echo area.  The mode line is in inverse video if
the terminal supports that, starts and ends with dashes, and contains text
like `Emacs: SOMETHING'.

  If a mode line has something else in place of `Emacs: SOMETHING',
then the window above it is in a special subsystem such as Dired.  The mode
line then indicates the status of the subsystem.

  Normally, the mode line has the following appearance:

     --CH-Emacs: BUF      (MAJOR MINOR)----POS------

This gives information about the buffer being displayed in the window: the
buffer's name, what major and minor modes are in use, whether the buffer's
text has been changed, and how far down the buffer you are currently
looking.

  CH contains two stars `**' if the text in the buffer has been
edited (the buffer is "modified"), or `--' if the buffer has not been
edited.  Exception: for a read-only buffer, it is `%%'.

  BUF is the name of the window's chosen "buffer".  The chosen buffer
in the selected window (the window that the cursor is in) is also Emacs's
selected buffer, the one that editing takes place in.  When we speak of
what some command does to "the buffer", we are talking about the
currently selected buffer.  *Note Buffers::.

  POS tells you whether there is additional text above the top of the
screen, or below the bottom.  If your file is small and it is all on the
screen, POS is `All'.  Otherwise, it is `Top' if you are looking at the
beginning of the file, `Bot' if you are looking at the end of the file, or
`NN%', where NN is the percentage of the file above the top of the screen.

  MAJOR is the name of the "major mode" in effect in the buffer.  At any
time, each buffer is in one and only one of the possible major modes.  The
major modes available include Fundamental mode (the least specialized),
Text mode, Lisp mode, and C mode.  *Note Major Modes::, for details of how
the modes differ and how to select one.

  MINOR is a list of some of the "minor modes" that are turned on
at the moment in the window's chosen buffer.  `Fill' means that Auto
Fill mode is on.  `Abbrev' means that Word Abbrev mode is on.
`Ovwrt' means that Overwrite mode is on.  *Note Minor Modes::, for more
information.  `Narrow' means that the buffer being displayed has
editing restricted to only a portion of its text.  This is not really a
minor mode, but is like one.  *Note Narrowing::.  `Def' means that a
keyboard macro is being defined.  *Note Keyboard Macros::.

  Some buffers display additional information after the minor modes.  For
example, Rmail buffers display the current message number and the total
number of messages.  Compilation buffers and Shell mode display the status
of the subprocess.

  In addition, if Emacs is currently inside a recursive editing level,
square brackets (`[...]') appear around the parentheses that surround the
modes.  If Emacs is in one recursive editing level within another, double
square brackets appear, and so on.  Since this information pertains to
Emacs in general and not to any one buffer, the square brackets appear in
every mode line on the screen or not in any of them.  *Note Recursive
Edit::.

  Emacs can optionally display the time and system load in all mode lines.
To enable this feature, type `M-x display-time'.  The information added
to the mode line usually appears after the file name, before the mode names
and their parentheses.  It looks like this:

     HH:MMpm L.LL [D]

(Some fields may be missing if your operating system cannot support them.)
HH and MM are the hour and minute, followed always by `am'
or `pm'.  L.LL is the average number of running processes in the
whole system recently.  D is an approximate index of the ratio of
disk activity to cpu activity for all users.

The word `Mail' appears after the load level if there is mail for
you that you have not read yet.

  Customization note: the variable `mode-line-inverse-video' controls
whether the mode line is displayed in inverse video (assuming the terminal
supports it); `nil' means no inverse video.  The default is `t'.



File: emacs  Node: Characters, Prev: Screen, Up: Top, Next: Keys

The Emacs Character Set
=======================

  GNU Emacs uses the ASCII character set, which defines 128 different
character codes.  Some of these codes are assigned graphic symbols such as
`a' and `='; the rest are control characters, such as `Control-a' (also
called `C-a' for short).  `C-a' gets its name from the fact that you type
it by holding down the CTRL key and then pressing `a'.  There is no
distinction between `C-a' and `C-A'; they are the same character.

  Some control characters have special names, and special keys you can type
them with: RET, TAB, LFD, DEL and ESC.  The space character is usually
referred to below as SPC, even though strictly speaking it is a graphic
character whose graphic happens to be blank.

  Emacs extends the 7-bit ASCII code to an 8-bit code by adding an extra
bit to each character.  This makes 256 possible command characters.  The
additional bit is called Meta.  Any ASCII character can be made Meta;
examples of Meta characters include `Meta-a' (`M-a', for short), `M-A' (not
the same character as `M-a', but those two characters normally have the
same meaning in Emacs), `M-RET', and `M-C-a'.  For traditional reasons,
`M-C-a' is usually called `C-M-a'; logically speaking, the order in which
the modifier keys CTRL and META are mentioned does not matter.

  Some terminals have a META key, and allow you to type Meta characters by
holding this key down.  Thus, `Meta-a' is typed by holding down META and
pressing `a'.  The META key works much like the SHIFT key.  Such a key is
not always labeled META, however, as this function is often a special
option for a key with some other primary purpose.

  If there is no META key, you can still type Meta characters using
two-character sequences starting with ESC.  Thus, to enter `M-a', you could
type `ESC a'.  To enter `C-M-a', you would type `ESC C-a'.  ESC is allowed
on terminals with Meta keys, too, in case you have formed a habit of using
it.

  Emacs believes the terminal has a META key if the variable
`meta-flag' is non-`nil'.  Normally this is set automatically
according to the termcap entry for your terminal type.  However, sometimes
the termcap entry is wrong, and then it is useful to set this variable
yourself.  *Note Variables::, for how to do this.

  Emacs buffers also use an 8-bit character set, because bytes have 8 bits,
but only the ASCII characters are considered meaningful.  ASCII graphic
characters in Emacs buffers are displayed with their graphics.  LFD
is the same as a newline character; it is displayed by starting a new line.
TAB is displayed by moving to the next tab stop column (usually every
8 columns).  Other control characters are displayed as a caret (`^')
followed by the non-control version of the character; thus, `C-a' is
displayed as `^A'.  Non-ASCII characters 128 and up are displayed with
octal escape sequences; thus, character code 243 (octal), also called
`M-#' when used as an input character, is displayed as `\243'.


File: emacs  Node: Keys, Prev: Characters, Up: Top, Next: Commands

Keys
====

  A "complete key"---where `key' is short for "key sequence"---is a
sequence of keystrokes that are understood by Emacs as a unit, as a single
command (possibly undefined).  Most single characters constitute complete
keys in the standard Emacs command set; there are also some multi-character
keys.  Examples of complete keys are `C-a', `X', RET, `C-x C-f' and `C-x 4
C-f'.

  A "prefix key" is a sequence of keystrokes that are the beginning of
a complete key, but not a whole one.  Prefix keys and complete keys are
collectively called "keys".

  A prefix key is the beginning of a series of longer sequences that are
valid keys; adding any single character to the end of the prefix gives a
valid key, which could be defined as an Emacs command, or could be a prefix
itself.  For example, `C-x' is standardly defined as a prefix, so
`C-x' and the next input character combine to make a two-character key.
There are 256 different two-character keys starting with `C-x', one for
each possible second character.  Many of these two-character keys starting
with `C-x' are standardly defined as Emacs commands.  Notable examples
include `C-x C-f' and `C-x s' (*Note Files::).

  Adding one character to a prefix key does not have to form a complete
key.  It could make another, longer prefix.  For example, `C-x 4' is itself
a prefix that leads to 256 different three-character keys, including `C-x 4
f', `C-x 4 b' and so on.  It would be possible to define one of those
three-character sequences as a prefix, creating a series of four-character
keys, but we did not define any of them this way.

  By contrast, the two-character sequence `C-f C-k' is not a key, because
the `C-f' is a complete key in itself.  It's impossible to give `C-f C-k'
an independent meaning as a command as long as `C-f' retains its meaning.
`C-f C-k' is two commands.

  All told, the prefix keys in Emacs are `C-c', `C-x', `C-h', `C-x 4', and
ESC.  But this is not built in; it is just a matter of Emacs's standard key
bindings.  In customizing Emacs, you could make new prefix keys, or
eliminate these.  *Note Key Bindings::.

  Whether a sequence is a key can be changed by customization.  For
example, if you redefine `C-f' as a prefix, `C-f C-k' automatically
becomes a key (complete, unless you define it too as a prefix).
Conversely, if you remove the prefix definition of `C-x 4', then
`C-x 4 f' (or `C-x 4 ANYTHING') is no longer a key.


File: emacs  Node: Commands, Prev: Keys, Up: Top, Next: Entering Emacs

Keys and Commands
=================

  This manual is full of passages that tell you what particular keys do.
But Emacs does not assign meanings to keys directly.  Instead, Emacs
assigns meanings to "functions", and then gives keys their meanings by
"binding" them to functions. 

  A function is a Lisp object that can be executed as a program.  Usually
it is a Lisp symbol which has been given a function definition; every
symbol has a name, usually made of a few English words separated by dashes,
such as `next-line' or `forward-word'.  It also has a
"definition" which is a Lisp program; this is what makes the function
do what it does.  Only some functions can be the bindings of keys; these
are functions whose definitions use `interactive' to specify how to
call them interactively.  Such functions are called "commands", and
their names are "command names".  More information on this subject will
appear in the GNU Emacs Lisp Manual (which is not yet written).

  The bindings between keys and functions are recorded in various tables
called "keymaps".  *Note Keymaps::.

  When we say that "`C-n' moves down vertically one line" we are glossing
over a distinction that is irrelevant in ordinary use but is vital in
understanding how to customize Emacs.  It is the function `next-line' that
is programmed to move down vertically.  `C-n' has this effect because it is
bound to that function.  If you rebind `C-n' to the function `forward-word'
then `C-n' will move forward by words instead.  Rebinding keys is a common
method of customization.

  In the rest of this manual, we usually ignore this subtlety to keep
things simple.  To give the customizer the information he needs, we
state the name of the command which really does the work in parentheses
after mentioning the key that runs it.  For example, we will say that
"The command `C-n' (`next-line') moves point vertically down,"
meaning that `next-line' is a command that moves vertically down
and `C-n' is a key that is standardly bound to it.

  While we are on the subject of information for customization only, it's a
good time to tell you about "variables".  Often the description of a
command will say, "To change this, set the variable `mumble-foo'."
A variable is a name used to remember a value.  Most of the variables
documented in this manual exist just to facilitate customization: some
command or other part of Emacs examines the variable and behaves
differently accordingly.  Until you are interested in customizing, you can
ignore the information about variables.  When you are ready to be
interested, read the basic information on variables, and then the
information on individual variables will make sense.  *Note Variables::.


File: emacs  Node: Entering Emacs, Prev: Commands, Up: Top, Next: Exiting

Entering and Exiting Emacs
**************************

  The usual way to invoke Emacs is just to type `emacs RET' at
the shell.  Emacs clears the screen and then displays an initial advisor
message and copyright notice.  You can begin typing Emacs commands
immediately afterward.

  Some operating systems insist on discarding all type-ahead when Emacs
starts up; they give Emacs no way to prevent this.  Therefore, it is
wise to wait until Emacs clears the screen before typing your first
editing command.

  Before Emacs reads the first command, you have not had a chance to give a
command to specify a file to edit.  But Emacs must always have a current
buffer for editing.  In an attempt to do something useful, Emacs presents a
buffer named `*scratch*' which is in Lisp Interaction mode; you can
use it to type Lisp expressions and evaluate them, or you can ignore that
capability and simply doodle.  (You can specify a different major mode for
this buffer by setting the variable `initial-major-mode' in your init
file.  *Note Init File::.)

  It is also possible to specify files to be visited, Lisp files to be
loaded, and functions to be called, by giving Emacs arguments in the
shell command line.  *Note Command Switches::.


File: emacs  Node: Exiting, Prev: Entering Emacs, Up: Top, Next: Command Switches

Exiting Emacs
=============

  There are two commands for exiting Emacs because there are two kinds of
exiting: "suspending" Emacs and "killing" Emacs.  "Suspending" means
stopping Emacs temporarily and returning control to its superior (usually
the shell), allowing you to resume editing later in the same Emacs job,
with the same files, same kill ring, same undo history, and so on.  This is
the usual way to exit.  "Killing" Emacs means destroying the Emacs job.
You can run Emacs again later, but you will get a fresh Emacs; there is no
way to resume the same editing session after it has been killed.

`C-z'     
     Suspend Emacs (`suspend-emacs').
`C-x C-c'     
     Kill Emacs (`save-buffers-kill-emacs').

  To suspend Emacs, type `C-z' (`suspend-emacs').  This takes
you back to the shell from which you invoked Emacs.  You can resume
Emacs with the command `%emacs' if you are using the C shell.

  On systems that do not permit programs to be suspended, `C-z' runs an
inferior shell that communicates directly with the terminal, and Emacs
waits until you exit the subshell.  The only way on these systems to get
back to the shell from which Emacs was run (to log out, for example) is to
kill Emacs.  `C-d' or `exit' are typical commands to exit a
subshell.

  To kill Emacs, type `C-x C-c' (`save-buffers-kill-emacs').  A
two-character key is used for this to make it harder to type.  Unless a
numeric argument is used, this command first offers to save any modified
buffers.  If you do not save them all, it asks for reconfirmation with
`yes' before killing Emacs, since any changes not saved before that will be
lost forever.  Also, if any subprocesses are still running, `C-x C-c'
asks for confirmation about them, since killing Emacs will kill the
subprocesses immediately.

  In most programs running on Unix, certain characters may instantly
suspend or kill the program.  (In Berkeley Unix these characters are
normally `C-z' and `C-c'.)  This Unix feature is turned off
while you are in Emacs.  The meanings of `C-z' and `C-x C-c' as
keys in Emacs were inspired by the standard Berkeley Unix meanings of
`C-z' and `C-c', but that is their only relationship with
Unix.  You could customize these keys to do anything (*Note Keymaps::).



File: emacs  Node: Command Switches, Prev: Exiting, Up: Top, Next: Basic

Command Line Switches and Arguments
===================================

  
  GNU Emacs supports command line arguments to request various actions
when invoking Emacs.  These are for compatibility with other editors and
for sophisticated activities.  They are not needed for ordinary editing
with Emacs, so new users can skip this section.

  You may be used to using command line arguments with other editors
to specify which file to edit.  That's because many other editors are
designed to be started afresh each time you want to edit.  You
edit one file and then exit the editor.  The next time you want to edit
either another file or the same one, you must run the editor again.
With these editors, it makes sense to use a command line argument
to say which file to edit.

  The recommended way to use GNU Emacs is to start it only once, just after
you log in, and do all your editing in the same Emacs process.  Each time
you want to edit a different file, you visit it with the existing Emacs,
which eventually comes to have many files in it ready for editing.  Usually
you do not kill the Emacs until you are about to log out.

  When files are nearly always read into an editor already running,
command line arguments for specifying a file when the editor is started
become fairly useless.

  Emacs accepts command-line arguments that specify files to visit,
functions to call, and other activities and operating modes.

  The command arguments are processed in the order they appear in the
command argument list; however, certain arguments (the ones in the second
table) must be at the front of the list if they are used.

  Here are the arguments allowed:

`FILE'     
     Visit FILE using `find-file'.  *Note Visiting::.
     
`+LINENUM FILE'     
     Visit FILE using `find-file', then go to line number
     LINENUM in it.
     
`-l FILE'     
`-load FILE'     
     Load a file FILE of Lisp code with the function `load'.
     *Note Lisp Libraries::.
     
`-f FUNCTION'     
`-funcall FUNCTION'     
     Call Lisp function FUNCTION with no arguments.
     
`-i FILE'     
`-insert FILE'     
     Insert the contents of FILE into the current buffer.
     This is like what `M-x insert-buffer' does; *Note Misc File Ops::.
     
`-kill'     
     Exit from Emacs without asking for confirmation.

  The remaining switches are recognized only at the beginning of the
command line.  If more than one of them appears, they must appear in the
order that they appear in this table.

`-t DEVICE'     
     Use DEVICE as the device for terminal input and output.
     
`-d DISPLAY'     
     When running with the X window system, use the display named DISPLAY
     to make the window that serves as Emacs's terminal.
     
`-batch'     
     Run Emacs in "batch mode", which means that the text being edited is
     not displayed and the standard Unix interrupt characters such as `C-z'
     and `C-c' continue to have their normal effect.  Emacs in batch mode
     outputs to `stdout' only what would normally be printed in the echo
     area under program control.
     
     Batch mode is used for running programs written in Emacs Lisp from
     shell scripts, makefiles, and so on.  Normally the `-l' switch
     or `-f' switch will be used as well, to invoke a Lisp program
     to do the batch processing.
     
     `-batch' implies `-q' (do not load an init file).  It also causes
     Emacs to kill itself after all command switches have been processed.  In
     addition, auto-saving is not done except in buffers for which it has been
     explicitly requested.
     
`-q'     
`-no-init-file'     
     Do not load your Emacs init file `~/.emacs'.
     
`-u USER'     
`-user USER'     
     Load USER's Emacs init file `~USER/.emacs' instead of
     your own.

  Note that the init file can get access to the command line argument
values as the elements of a list in the variable `command-line-args'.
(The arguments in the second table above will already have been processed
and will not be in the list.)  The init file can override the normal
processing of the other arguments by setting this variable.

  One way to use command switches is to visit many files automatically:

     emacs *.c

passes each `.c' file as a separate argument to Emacs, so that Emacs
visits each file (*Note Visiting::).
  
  Here is an advanced example that assumes you have a Lisp program
file called `hack-c-program.el' which, when loaded, performs some
useful operation on current buffer, expected to be a C program.

     emacs -batch foo.c -l hack-c-program -f save-buffer -kill > log

Here Emacs is told to visit `foo.c', load `hack-c-program.el'
(which makes changes in the visited file), save `foo.c' (note that
`save-buffer' is the function that `C-x C-s' is bound to), and
then exit to the shell that this command was done with.  `-batch'
guarantees there will be no problem redirecting output to `log',
because Emacs will not assume that it has a display terminal to work with.

